1. Field of the Invention
The present invention relates to the field of surgery. More particularly, the present invention relates to a directional indicator and methods for use in determining the orientation of radiation to be emitted from a side-firing laser fiber utilized in conjunction with an instrument such as an endoscope or laparoscope during examination or surgery.
2. Background Art
Endoscopes, laparoscopes, and other optical examination instruments are utilized to provide visual images to a surgeon regarding the condition of tissue surrounding the distal end of the instrument. The images provided by an examination utilizing one of these instruments can be used to allow surgery utilizing devices incorporated into the instrument or to determine whether more invasive surgery is indicated.
To perform surgery, ancillary devices such as forceps, drills or laser fibers have been incorporated into the endoscopes or laparoscopes By utilizing the visual imaging provided by the endoscope or laparoscope, a surgeon can perform surgery at sites within the body in a manner which is much less invasive than conventional surgery. Even when a naturally occurring orifice is not available to provide access to the surgical area, only a small incision need be created to provide access for a laparoscope.
Another benefit of utilizing endoscopic or laparoscopic examination is that this type of examination or surgery may often be performed using only local anesthesia, resulting in a shorter recovery time for a patient than when utilizing anesthesia which acts upon the central nervous system. In addition, since endoscopic surgery is less invasive, recovery from the surgery is also expedited.
As a result of the benefits of incorporating devices into the endoscope to provide these less-invasive methods for surgery, operations such as gall bladder removal, biopsies, and tumor removal are often accomplished on an outpatient is.
One initial problem encountered when incorporating ancillary devices into the endoscope or laparoscope has been determining the direction at which the forceps or laser fibers are oriented relative to the optical or imaging portion of the endoscope or laparoscope. This is especially important when using side-firing laser fibers wherein the direction of radiation can be emitted at one or more points throughout a 360 degree range. Determining the orientation of radiation to be emitted is especially important since the radiation itself is typically invisible and only the effects of the radiation can be observed.
To assist in the determination of the orientation of the invisible laser beam, a second visible aiming beam, (for example, an HeNe beam) is utilized. The primary, invisible laser beam that does the cutting or removing of tissue is oriented in the identical direction as the visible aiming beam. The physician or surgeon observes the visible nondestructive aiming beam and directs that beam to the desired tissue prior to activating the invisible laser beam.
Another technique utilized to determine the direction of side-firing laser beams is employed in those side-firing laser fibers having a reflector to divert the primary operating beam. In these cases, the orientation of the reflector itself provides the surgeon with the orientation of the side-fired radiation.
Although both the reflector technique and aiming beam technique provide visual feedback to the surgeon regarding the direction of the radiation to be emitted, these techniques are not available when surgery is being performed in tissue which obscures the reflector in the distal tip of the laser fiber or in the case of the aiming beam, when the operating site is overly bloody. Because the aiming beam is commonly an HeNe beam, the beam is red and tends to become difficult to distinguish if the operating site is bloody and thereby has a color similar to the aiming beam.
For example, when an endoscope is advanced into swollen tissue, the distal end of the laser fiber may become obscured from the view provided by the optical portion of the endoscope and the reflector or aiming beam cannot be seen. The direction of the radiation emitted, therefore, is indeterminate.
To overcome these obstacles when performing surgery in swollen tissue wherein the laser fiber is obscured from view and the direction of laser radiation to be emitted is thereby indeterminate, external clocking devices have been developed which are attached externally to the endoscope or laparoscope. These clocking devices are typically aligned with the radiation output of the side-firing laser fiber and are secured in this position to the proximal end of the instrument before the instrument is inserted into the body of the patient.
To utilize a clocking device, the physician diverts his attention from the monitor displaying the operating field (as received from the optical portion of the instrument) to the proximal end of the endoscope. This provides the surgeon with the ability to determine the direction of the radiation even when no observed tissue effect can be ascertained.
In the past, clocking devices have been as simple as attaching the laser fiber to the endoscope or laparoscope. In this permanent relationship the endoscope itself may be used as the clocking device to achieve rotation of the fiber in an ascertainable manner relative to an ascertained starting position. More complex versions of clocking devices utilize a handle attached to the laser fiber with a ratcheting mechanism interrelating with the endoscope to indicate the position of the laser fiber and handle relative to the position of the proximal end of the endoscope.
Use of such clocking devices, however, requires the physician to frequently divert attention from the monitor to the proximal end of the endoscope in order to determine the position of the laser fiber so that the orientation of the radiation to be emitted can be gauged.
A separate problem associated with the use of an endoscope or laparoscope is encountered when a physician attempts to determine the absolute size of anomalous tissues appearing in the viewing area. Absolute measurements are often valuable in order to evaluate the size of a tumor or other tissues to determine whether or not more invasive surgery is indicated. Such absolute measurements are difficult to obtain when viewed through the endoscope as no references are available with which to compare the size of the anomalous tissue.